Effect of limited tryptic modification of a bacterial poly(3-hydroxybutyrate) depolymerase on its catalytic activity

摘要: Abstract The extracellular poly(3-hydroxybutyrate) depolymerase of Alcaligenes faecalis Tl, which hydrolyzes both hydrophobic and water-soluble oligomers d (−)-3-hydroxybutyrate, lost its hydrolyzing activity toward the substrate on mild trypsin treatment, but retained oligomers. molecular mass trypsin-treated enzyme was 44 kDa, as estimated by polyacrylamide gel electrophoresis in presence sodium dodecyl sulfate, 6 kDa smaller than that native (50 kDa). seemed to be less one, because it rather weakly adsorbed a butyl-Toyopearl column compared with enzyme, showed no ability bind poly(3-hydroxybutyrate), tightly bound. These results suggest that, addition catalytic site, has is not essential for hydrolysis oligomers, necessary substrates, this site removed from action trypsin.